OPTIMIZATION OF SURFACE PLASMON RESONANCE BASED BIOSENSOR USING SCFV (SINGLE-CHAINED FRAGMENT VARIABLE) RECOMBINANT RECEPTOR FOR COVID-19 DETECTION

• Main Author: Eko Nugroho, Antonius
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/55328
• Institution: Institut Teknologi Bandung

Detection of COVID-19 plays a significant role in reducing the transmission of the disease. Antibody test is the early generation of rapid test for COVID-19 in Indonesia. The accuracy of this method is quite low due to its detection targets which are antibodies, such as IgG and IgM. The body needs about 7-14 days from viral onset to produce those antibodies. On the contrary, the RT-PCR cannot be used as rapid test due to its time assays. Therefore, Indonesian government decided to start using antigen test as the rapid test. This method is targeting the spike protein of the virus, so the accuracy is improved and the time assays is kept low. Similar method using surface plasmon resonance was developed in this research as a quantified COVID-19 detection method for substituting the RT-PCR. In this research, the binding activity of SARS-CoV-2 RBD and scFv CR3022 which is produced by the Research Center of Molecular Biotechnology at Universitas Padjajaran in different types of ITM media was measured. The system using periplasm scFv protein and mixture of PBS with ITM VitPAD is the best system and has limit of detection (LOD) at 8.73 ng/mL, maximum responsse at 6.19 percent, and determination coefficient at 88 percent. Purification of scFv can increase the maximum responsse and the coefficient of determination to 8.02 and 92 percent respectively, as well as decrease the detection limit to 8.34 ng/mL. This biosensor has specificity at 88.47 percent for RBD of SARS-CoV-2, tested using samples containing RBD of other viruses. Moreover, it can be used for five times and stored in -4 centigrade freezer for up to three days. Further test using RT-PCR tested swab specimens shows that the developed quantified biosensor succeeds to detect the spike protein of SARS-CoV-2.